code: def __init__(self, *args, **kwargs):
      self._data_frequency = kwargs.pop("data_frequency", None)
  
      super(BcolzExchangeBarReader, self).__init__(*args, **kwargs)
  
file_path: catalyst/catalyst/exchange/exchange_bcolz.py
imports: import numpy
  from catalyst import get_calendar
  from catalyst.data.minute_bars import BcolzMinuteBarReader, BcolzMinuteBarWriter
label_desc: Use image node_id 1 to create a new BcolzExchangeBarReader object from inherited base classes: BcolzMinuteBarReader with example: obj = BcolzExchangeBarReader()